I'm not sure if this is a bug or whether I've misunderstood something, but there seems to be a problem with the definition of workspace sizes in dsyevd_gpu and dstedx.

In lines 262-267 of dsyevd_gpu.cpp the variable llwrk2 is defined and used as the input for lwork in the call to magma_dstedx on line 316. However, this value is too small unless lwork used to call magma_dsyevd_gpu is larger than 1 + 6n + 2*n^2.

Perhaps there is some reason why the lwork for dstedx has to be smaller than lwork for dsyevd_gpu, but if this is the case then perhaps the documentation can be updated to reflect this.

Ran into this as well so I rebuilt magma with debug info and ran under gdb. The first breakpoint is the function called in inquiry mode. Results are fed back into the second call and generate the same error you noted.